Obesity in childhood has been increasing at an alarming rate. For children ages 2-5 years, the prevalence of overweight children has almost tripled over the last three decades. Obesity is a multifactorial condition with varying causes including genetic, social, cultural, and behavioral factors, all of which may interact. The aims of the present proposal are to examine a number of these factors and their role in childhood obesity. The proposed study is a follow-up of an infant sample seen at 4, 6, 12 and 18 months of age when temperamental reactivity and parent use of food to soothe was assessed. In the present application we propose to investigate a core developmental construct, self- regulation, which demonstrates rapid growth during the preschool years. As young children develop the ability to regulate their behavior, parents begin to socialize children to rules and standards of behaving. In some instances, parents may turn to instrumental feeding, or the use of food to control or reward behavior. The health outcomes of this feeding practice is expected to be different based on the child's temperamental style and/or their self-regulatory ability. More specifically, instrumental feeding is expected to interact with the genetically-based temperament trait of surgency, which is characterized by a sensitive reward system, to increase the risk of childhood obesity. This hypothesis is guided by the central principle of the proposed study; that temperament is linked to health and adjustment either indirectly by evoking parenting responses or through interactions with parenting behaviors that may either buffer the negative effects or increase the risk for poor outcome. Toward this goal child temperamental reactivity, self-regulation and parenting will be assessed throughout the preschool years of life using multiple methods including laboratory visits, parent reports, and objective measurements. Childhood BMI and weight change are the proposed outcomes. Identifying modifiable factors present early in a child's life will contribute to more successful preventions aimed at reducing childhood and adult obesity.